Asp.net,
control,
File Uploads,
Server Control
FileUpload control properties :
- Enabled : Enables you to disable the FileUpload control.
- FileBytes : Enables you to get the uploaded file contents as a byte array.
- FileContent : Enables you to get the uploaded file contents as a stream.
- FileName : Enables you to get the name of the file uploaded.
- HasFile : Returns True when a file has been uploaded.
- PostedFile : Enables you to get the uploaded file wrapped in the HttpPostedFile object.
- Focus : Enables you to shift the form focus to the FileUpload control.
- SaveAs : Enables you to save the uploaded file to the file system.
The HttpPostedFile class has the following properties :
- ContentLength : Enables you to get the size of the uploaded file in bytes.
- ContentType : Enables you to get the MIME type of the uploaded file.
- FileName : Enables you to get the name of the uploaded file.
- InputStream : Enables you to retrieve the uploaded file as a stream.
- SaveAs : Enables you to save the uploaded file to the file system.
You can save a file by using either the FileUpload.SaveAs() method or the HttpPostedFile.SaveAs() method.<%@ Page Language=”C#” %>
<%@ Import Namespace=”System.IO” %>
<!DOCTYPE html PUBLIC “-//W3C//DTD XHTML 1.0 Transitional//EN”
“http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd”>
<script runat=”server”>
protected void btnAdd_Click(object sender, EventArgs e)
{
if (ImageUpload.HasFile)
{
if (CheckFileType(ImageUpload.FileName))
{
String filePath = “~/UploadImages/” + ImageUpload.FileName;
ImageUpload.SaveAs(MapPath(filePath));
}
}
}
bool CheckFileType(string fileName)
{
string ext = Path.GetExtension(fileName);
switch (ext.ToLower())
{
case “.gif”:
return true;
case “.png”:
return true;
case “.jpg”:
return true;
case “.jpeg”:
return true;
default:
return false;
}
}
void Page_PreRender()
{
string upFolder = MapPath(“~/UploadImages/”);
DirectoryInfo dir = new DirectoryInfo(upFolder);
dlstImages.DataSource = dir.GetFiles();
dlstImages.DataBind();
}
</script>
<html xmlns=”http://www.w3.org/1999/xhtml” >
<head id=”Head1” runat=”server”>
<title>FileUpload File</title>
</head>
<body>
<form id=”form1” runat=”server”>
<div>
<asp:Label id=”lblImageFile” Text=”Image File:” AssociatedControlID=”ImageUpload” Runat=”server” />
<asp:FileUpload id=”ImageUpload” Runat=”server” />
<br /><br />
<asp:Button id=”btnAdd” Text=”Add Image” OnClick=”btnAdd_Click” Runat=”server” />
</div>
</form>
</body>
</html>
The page includes a method named CheckFileType(), which prevents users from uploading a file that does not have the .gif, .jpeg, .jpg, or .png extension. The method restricts the type of file that can be uploaded based on the file extension.
